Tucked away in the rocky countryside northwest of Cuzco, Peru, Machu Picchu is believed to have been a royal estate or sacred religious site for Inca leaders, whose civilization was virtually wiped out by Spanish invaders in the 16th century. For hundreds of years, until the American archaeologist Hiram Bingham stumbled upon it in 1911, the abandoned citadel’s existence was a secret known only to peasants living in the region.